15 states still reporting highest levels of ILI activity
At least 15 states are still reporting the highest levels of influenza-like activity even as the percentage of patient visits attributed to ILI dropped to 3.7%. Judging from the second consecutive sharp week-to-week drop in ILI rates nationwide, the season may officially end in the next week or two even as pockets of the nation still contend with a virulent flu season.
Current data indicate that the 2017-2018 flu season peaked at 7.5% in early February (during week 5) and is now on the decline. However 34 states plus Puerto Rico continue to report widespread flu activity and 21 states plus New York City continue to experience high influenza-like illness activity.
"This flu season has been particularly hard," FDA Commissioner Scott Gottlieb testified before the U.S. House Committee on Energy and Commerce on Thursday during a review of national response efforts to this past season. "This year is not the first time we’ve seen vaccines be less effective against H3N2. Recent flu vaccines have proven on average only about 33% effective against H3N2 viruses. Given this, we’re looking at several factors to better understand why effectiveness tends to be lower against this strain."
While H3N2 viruses remain predominant overall this season, the proportion of B viruses versus A viruses is now about even. In recent weeks, B viruses have been increasing while H3N2 viruses have been decreasing. Early vaccine effectiveness estimates show that flu vaccine has reduced the risk of having to go to the doctor due to flu by 36% overall through Feb. 3, 2018. Effectiveness against H3N2 viruses this season was 25%. Effectiveness against H1N1 was 67% and against B viruses it was 42%.
The FDA is presently exploring the development of a universal vaccine, though a marketable univeral vaccine is still years off, Gottlieb suggested. The FDA is also investigating efficacy studies between cell-based vaccines and egg-based vaccines.
For the current season, the overall hospitalization rate and all age-specific hospitalization rates are now higher than the end-of-season hospitalization rates for 2014-2015; a high severity, H3N2-predominant season. CDC also reported an additional 5 flu-related pediatric deaths during week 9, bringing the total number of flu-related pediatric deaths reported this season to 119.
According to the CDC, flu activity is likely to remain elevated for several more weeks.
Current data indicate that the 2017-2018 flu season peaked at 7.5% in early February (during week 5) and is now on the decline. However 34 states plus Puerto Rico continue to report widespread flu activity and 21 states plus New York City continue to experience high influenza-like illness activity.
"This flu season has been particularly hard," FDA Commissioner Scott Gottlieb testified before the U.S. House Committee on Energy and Commerce on Thursday during a review of national response efforts to this past season. "This year is not the first time we’ve seen vaccines be less effective against H3N2. Recent flu vaccines have proven on average only about 33% effective against H3N2 viruses. Given this, we’re looking at several factors to better understand why effectiveness tends to be lower against this strain."
While H3N2 viruses remain predominant overall this season, the proportion of B viruses versus A viruses is now about even. In recent weeks, B viruses have been increasing while H3N2 viruses have been decreasing. Early vaccine effectiveness estimates show that flu vaccine has reduced the risk of having to go to the doctor due to flu by 36% overall through Feb. 3, 2018. Effectiveness against H3N2 viruses this season was 25%. Effectiveness against H1N1 was 67% and against B viruses it was 42%.
The FDA is presently exploring the development of a universal vaccine, though a marketable univeral vaccine is still years off, Gottlieb suggested. The FDA is also investigating efficacy studies between cell-based vaccines and egg-based vaccines.
For the current season, the overall hospitalization rate and all age-specific hospitalization rates are now higher than the end-of-season hospitalization rates for 2014-2015; a high severity, H3N2-predominant season. CDC also reported an additional 5 flu-related pediatric deaths during week 9, bringing the total number of flu-related pediatric deaths reported this season to 119.
According to the CDC, flu activity is likely to remain elevated for several more weeks.